1. Field of the Invention
The present invention relates to a clean room-suitable linear guide. In operation, such linear guides release as few particles as possible, so that the clean room does not become contaminated.
2. Description of the Related Art
The manufacture of integrated circuits is done today in so-called clean rooms, since the contamination of a wafer, with even the smallest particles, can lead to failure of the circuits to be manufactured. For all the devices and machines used in a clean room, there is accordingly the requirement that as few particles as possible be generated.
Since during the manufacturing process wafers have to be moved, it is not possible to dispense with moving parts. The use of air bearings, which operate in contactless fashion and thus without abrasion, is not always possible for reasons of cost. Thus, guides are also used that are based on conventional bearings, such as ball bearings or slide bearings. Even if such bearings are made from especially low-abrasion materials, the formation of particles cannot be avoided. Apparatuses are therefore known in which particles that occur are vacuumed away by a vacuum device before they can get into the surroundings and contaminate the clean room.
U.S. Pat. No. 4,955,244, for instance, describes a clean room-suitable apparatus with a linear drive resting on a recirculating ball spindle. At the rotor, particles generated in the interior of its housing are vacuumed away through an opening in the housing. For that purpose, a vacuum device is attached to the lubrication nipple of the housing.